Conventional keyboards for computers, typewriters, or similar machines typically have a set of keys all aligned substantially in a single plane that may be flat or slightly tilted toward the operator. The standard QWERTY key format used by the majority of operators throughout the world has three rows of ten keys in standard positions and arranges the alphabetic keys in parallel rows and parallel columns. The alphabetic keys include the 26 letter keys and typically four punctuation keys, i.e., ";", ",", "." and "/" or "?". In addition to the alphabetic keys, conventional keyboards may also have numeric and/or function keys which are typically located above, below, or on one or both sides of the alphabetic keys. The function keys may typically include, for example, the tab, shift, and return keys as well as the alt, control, and option keys.
During the typing operation, the operator's forearms are positioned at inwardly directed angles from the operator's sides toward the keyboard, with the palms down and the hands generally flat. The wrists are bent and the hands are angled outwardly relative to the forearms in order to align the operator's fingers in directions running from the front to the back of the keyboard. The fingers move in narrow parallel lines from the lower left to the upper right of the keyboard. This is not a natural, normal or restful position for human hands and fingers. The wrists tend to be naturally unbent or straight and in alignment with the forearm, not at the angle required for typing on a conventional keyboard, and the fingers tend to be slightly spread and move in a fan-like orientation.
Adverse physical conditions may arise in the operator's wrists, hands and fingers resulting from the repetitive motions associated with typing, particularly for long periods on any given day or successive days. Such adverse conditions are compounded by the crude design of conventional keyboards which forces the orientation of the operator's wrists, hands and fingers into particularly awkward and unnatural angles for prolonged periods of time. Typing injuries may fall into one of a few overlapping categories: repetitive stress disorder, repetitive motion injury, cumulative trauma disorder, and carpal tunnel syndrome. These conditions often require medical attention and, in severe cases, the worker may be unable to perform normal work functions. The cost in human suffering, and on-going medical expenses may be severe.
Attempts to redesign the traditional keyboard, either by redesigning the construction of the keyboard or redesigning the arrangement of the keys, have been largely unsuccessful. The attempts to redesign the construction of the keyboard have included, for example, separating the keyboard into left and right portions so that the left and right portions can slide along on a track facing the operator or pivoting the left and right portions of keyboard so that they can be vertically inclined about each other. The attempts to redesign the arrangement of the keys have included, for example, separating the keys into left and right sections containing substantially parallel rows and parallel columns of keys or even completely rearranging the conventional position of the alphanumeric keys.
These design changes have not adequately accounted for the natural ergonomic orientation and movement of the human wrists, hands and particularly the fingers during the typing operation. For example, in the designs which have separated the left and right sections so that each section can be vertically pivoted about each other, the hands are inherently unstable when positioned in the vertical planes. The operator's hands may become tired and strained if elevated too long. Further, it is difficult to see the keys in both sections when each portion of the keyboard is facing in opposite directions. The designs typically have numerous parts which are expensive to manufacture and relatively difficult to assemble. The rearrangement of the standard position of the keys also requires substantial operator retraining.